The present invention relates generally to motor control systems and, more particularly, to a method and apparatus for disabling ports in a motor control system.
Rotating motors are typically controlled by a motor drive that receives reference signals and motor feedback signals and outputs a torque signal that is applied to the motor. The torque signal is adjusted base don the feedback signals to ensure that the motor rotates at the desired velocity.
Modern motor control systems include networked environments, where information may be provided to the motor drive from multiple sources coupled to the network. For example, control messages (e.g., “START”, “STOP”, “JOG”, etc.) may be received from various sources, such as a local pushbutton or control panel, a networked workstation, an industrial controller, etc. Furthermore, other messages may be received for configuring the motor drive, thereby altering its settings relating to the configuration of the controlled motor or the internal algorithms it uses for adjusting the torque signal, for example.
Commonly, a motor drive includes a plurality of ports for communicating messages with other network entities. Local ports may be provided for connecting a human interface module (HIM) including a display screen and a keypad or other input device. Other ports may be coupled to the network through various interface circuitry to communicate with remote devices. Still other ports may be flexible, accepting either a local or remote interface.
The peripheral devices coupled to the ports serve various purposes, including monitoring, communication, configuration, control, and data collection. These functions may be changed as the system is reconfigured and peripheral devices are added or replaced with different peripherals. In certain motor control systems, a high level of security may be desired to control the access available to the peripheral devices for affecting the configuration or control of the motor control system. Previously, this security may have been provided through a locked cabinet or other physical barrier. For network ports, security may be provided through the general password functions of the computer system. As the number and flexibility of ports used to communicate with a motor drive increases, it becomes more difficult to maintain the effectiveness of physical barriers or general network security measures in preventing unauthorized access.
This section of this document is intended to introduce various aspects of art that may be related to various aspects of the present invention described and/or claimed below. This section provides background information to facilitate a better understanding of the various aspects of the present invention. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.